I liked the two 1992 films (The Lost World
and Return to the Lost World
) with John Rhys-Davies as Challenger and David Warner as Summerlee.
I don't think a faithful adaptation is as important as a good adaptation. If you want the original, read the book. It's called an adaptation for a reason. To adapt something is to change it to fit new needs or circumstances. It's not the goal of a movie based on a book to slavishly copy the book, but to use the book as a starting point for creating a good movie.